This invention relates to the preparation of low ammonium or alkylammonium salts of alkanesulfonamides and their analogues. More particularly, it relates to a method for converting substantially all of the ammonium or alkylammonium salt impurities of an alkanesulfonamide to the corresponding alkali-metal or alkaline-earth metal salts.
In the preparation of alkanesulfonamides, or otherwise, the alkanesulfonamides may become contaminated with the ammonium or amine salts of the reaction by-products. Due to their incorporation in reaction amines, these salts may cause the formation of other unwanted by-products when the contaminated sulfonamide is employed in certain syntheses. This invention provides a method of reducing the ammonium or alkylammonium ion content of the contaminated sulfonamide by replacement of the ammonium or alkylammonium ions with alkali-metal or alkaline-earth metal ions. After such a treatment, the alkanesulfonamide may then be included in various subsequent synthetic reactions without the formation of unwanted by-products.